<!-- 返回顶部  -->
<d-back-top [customTemplate]="customTemplate" [visibleHeight]="10">
  <ng-template #customTemplate>
    <div class="devui-backtop-custom" dTooltip [content]="'返回顶部'" [position]="'left'">
      <span class="icon-chevron-up"></span>
    </div>
  </ng-template>
</d-back-top>